Today we have a guest post from the expert goldfish breeders Adam and Erica Till in Calgary, Alberta Canada.
They’re going to give you some great tips for growing out fry from eggs to happy baby fish.
Raising Baby Goldfish
When you were feeding your goldfish this morning you noticed that they were chasing each other quite a lot, and when you came back a few hours later all your plastic plants and ornaments were covered in little round clear balls.
Looking closer, you realized that they’d laid eggs!
What are you supposed to do now?
Although goldfish are generally very sweet-natured fish, they almost universally make terrible parents. In fact, it’s not unusual to watch other goldfish in the tank following closely behind the spawning pair happily munching away on the eggs that are being laid.
As a result, if your goldfish spawn and you want to raise babies, you need to get the newly laid eggs out of the parents’ tank as soon as possible.
Thankfully, fertilized eggs are very sticky, and if you’re able to temporarily remove your ornaments and plants to a spare aquarium (or even a plastic storage tub), you’ll give the developing babies the best chance of survival.
Just fill the extra tank with water that’s the same temperature as the main tank, add some dechlorinator, and add the egg-covered ornaments.
The Parents’ Tank
Once the eggs are safely stashed away from the parents, it’s time to do a BIG water change on the parents’ tank. Even if you have a cycled filter, nothing overwhelms a filter quicker and spikes nitrite levels faster than a spawning pair of goldfish!
No matter when you did your last water change, and especially if your tank is a little on the small side, it’s going to need quite a big water change immediately after you notice your goldfish spawning. The reason for this is that the milt released by the male goldfish and any extra eggs laid by the female that you might not have noticed will very quickly make the water quite toxic as they break down in the water.
If it’s been only a few days since your last water change, then at least a 50% water change is going to make sure your new goldfish parents stay healthy. If it’s been a while since your last water change (meaning the water might be a little dirty), doing daily 25% changes for 3-4 days would be a better option so that you don’t shock the parents with fresh water (changing out too much water on a dirty tank can harm the parents).
Saving As Many Eggs As Possible In the Main Tank
Although you’ll probably have more babies than you know what to do with anyway, your first instinct will probably be to try to save as many of the eggs that are still in the main tank as possible.
Vacuuming up any eggs that fall into the gravel is a good idea to prevent the main tank water from fouling anyway, but if you want to save them and try to hatch them out, vacuum them into a bucket rather than down the drain. If you carefully drain off the water and other waste, you can use a large syringe to suck them up without damaging them and then place them in your growout tank with the other eggs.
If the parents spawned near the tank wall and there are eggs attached to the glass (I told you they were sticky!), you can carefully use a credit card to scrape them off the side and into a bowl you hold underneath them.
You might worry about damaging them this way, but if it’s been at least an hour since the parents released them, the fertilized eggs will be surprisingly firm and rubbery.
If you’re careful you’ll save most of them, and the ones that break will tend to be the ones that wouldn’t have hatched anyway.
The Baby Tank
Now that you have the eggs safely squirreled away from the parents in a separate tank, the first thing you need to do is to drain the water in the egg tank to a level that only barely covers the ornaments. Babies need to have the shortest distance possible from where they hatch to the surface so that they can fill their swim bladders easily once they start swimming.
As a result, if you have an ornament that’s taller than it is wide place it in the tank on its side rather than standing up, and don’t bother about trying to “plant” any plants that you’ve moved into the tank covered in eggs (leaving them floating is fine).
If you happen to have a spare sponge filter (especially if it’s already cycled), by all means get that going in the egg tank. If you only have power filters like hang-on-back or cannister filters, only use them if you can cover the intake with some fine sponge to avoid sucking in brand new babies (believe me, they’re tiny!).
If you don’t have a spare filter, try to at least get an air stone bubbling in the tank.
The First Few Days
If you have access to a water test kit (or don’t mind taking a water sample to your fish store every few days), keep an eye on ammonia and nitrite levels in your baby tank. Try to keep both of those to 0ppm, which might take quite a lot of water changes to do if your spare filter isn’t cycled.
If you keep a close eye on the eggs, you’ll probably notice that some will be clear, and some will quickly turn cloudy or fuzzy. The clear ones are the ones that might be able to hatch, and the cloudy ones weren’t fertilized and can’t hatch. If you want to carefully remove the cloudy ones and can do so safely, go ahead and do that.
Should you be familiar with growing live baby brine shrimp, you can start your brine shrimp hatcheries going right away. If not, then try to find someone in your local area that can help you.
Within 3-7 days, if all goes well you should see your babies start to hatch.
As much as you might want to, there’s no point in feeding them for at least two days after they hatch, since the babies don’t actually have mouths yet and they’re still absorbing their egg sacs.
When the start clinging to the sides of the tank, you can start lightly feeding with live baby brine shrimp or other baby fish food.
As with bigger fish, the more frequently you feed them with small amounts of food, the quicker they’ll grow. It’s much better to feed them only as much as they can eat in a few minutes multiple times a day than it is to feed a lot of food only once or twice a day. Babies are tiny after all, and anything they can’t eat will just make the water dirty.
Finding Homes For Your Babies
If you’ve done your job correctly and you have a bunch of baby fish happily swimming around and growing up, you’ll want to try to find homes for as many of them as you can fairly soon.
After all, although you can keep a lot of baby fish in a small tank when they’re tiny, they’ll still grow into adults really quickly. If you remember the article here that says you need 20 gallons for the first goldfish and 10 gallons for each additional fish, you probably won’t have room for all the babies from even a single spawn once they grow up.
As tempting as it might be, one thing you can’t do is to release them into the wild or into a local pond or fountain. In addition to being against the law in most areas, the fish can have a terrible impact on local wildlife, and they can survive through all but the coldest winters.
To find more proper homes, sometimes a local fish store will exchange goldfish for store credit, or you can think about contacting any local fish clubs in the area to see if anyone has spare tank or pond space. Another option might be to connect with other hobbyists via Craigslist or Facebook, and that way you might even be able to make a new goldfish-crazy friend or two.
If you’ve reached this point congratulations, and great job being a new goldfish parent!
Erica and Adam Till
Arctic Lights Aquatics (https://arcticlightsaquatics.com)